{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,27]],"date-time":"2026-09-27T02:11:01Z","timestamp":1790475061028,"version":"4.1.0"},"reference-count":48,"publisher":"EDP Sciences","license":[{"start":{"date-parts":[[2020,2,7]],"date-time":"2020-02-07T00:00:00Z","timestamp":1581033600000},"content-version":"vor","delay-in-days":37,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Parasite"],"accepted":{"date-parts":[[2020,1,29]]},"published-print":{"date-parts":[[2020]]},"abstract":"<jats:p><jats:italic>Background<\/jats:italic>: Primary infection by<jats:italic>Toxoplasma gondii<\/jats:italic>in pregnant women can result in serious outcomes for the foetus. A false-positive IgG result during pregnancy can lead to a misdiagnosis of past infection and to stopping preventive measures. We collected 189 sera with positive Architect<jats:sup>\u00ae<\/jats:sup>Toxo IgG assay (Abbott Laboratories) and negative IgG results with at least two other serological tests, in order to find an explanation for the suspected false-positive IgG results. We used the<jats:italic>recom<\/jats:italic>Line Toxoplasma IgG<jats:sup>\u00ae<\/jats:sup>immunoblot (Mikrogen Diagnostik) to search for specific antigenic reactivities of the sera, and the LDBio Toxo II IgG<jats:sup>\u00ae<\/jats:sup>immunoblot (LDBio Diagnostics) as a confirmatory test.<jats:italic>Results<\/jats:italic>: The bands GRA8 and\/or GRA7 were positive for 148 samples (78.3%). GRA8 was the most frequent band, appearing in 133 patterns (70.4%), whereas GRA7 was present for 49 samples (25.9%). Of the 81 samples tested with LDBio<jats:sup>\u00ae<\/jats:sup>, 23 (28.4%) turned out to be positive. Of the 58 negative LDBio<jats:sup>\u00ae<\/jats:sup>tests (71.6%) (real false-positive Architect<jats:sup>\u00ae<\/jats:sup>IgG), 23 samples (39.6%) did not show either a GRA8 or p30 band by<jats:italic>recom<\/jats:italic>Line<jats:sup>\u00ae<\/jats:sup>. Their false positivity with Architect<jats:sup>\u00ae<\/jats:sup>remains unexplained since Abbott uses these two recombinant antigens for their assay.<jats:italic>Conclusions<\/jats:italic>: The Architect<jats:sup>\u00ae<\/jats:sup>IgG false positivity for<jats:italic>T. gondii<\/jats:italic>seems to be due to reactivity against GRA8 for the majority of the sera and GRA7 to a lesser extent. The hypothesis of past contact with parasites genetically close to<jats:italic>T. gondii<\/jats:italic>such as<jats:italic>Hammondia hammondi<\/jats:italic>or<jats:italic>Neospora caninum<\/jats:italic>seems promising and should be assessed further.<\/jats:p>","DOI":"10.1051\/parasite\/2020006","type":"journal-article","created":{"date-parts":[[2020,2,7]],"date-time":"2020-02-07T10:03:35Z","timestamp":1581069815000},"page":"7","source":"Crossref","is-referenced-by-count":23,"title":["Serological diagnosis of<i>Toxoplasma gondii<\/i>: analysis of false-positive IgG results and 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